1. Field of the Invention
The present invention relates to a lens driving apparatus that drives a zoom lens and an autofocus lens, which are used in a small-sized portable camera built into a digital camera, a cellular phone and the like.
2. Description of the Related Art
Conventionally, such a lens driving apparatus that performs both autofocusing and scaling with a zoom lens and a focus lens is known as disclosed in, for example, Unexamined Japanese Patent Publication Hei 7-140523. The lens driving apparatus in this conventional art converts a rotational movement using a ball screw and the like to a linear movement to move the lens in a direction of an optical axis.
By the way, in the lens driving apparatus, which is used in a small-sized portable camera, it is required that a lens be efficiently moved in a direction of an optical axis by a desired amount in a narrow space.
However, when structure in which rotational movement using the ball screw and the like is converted to linear movement to move the lens in the direction of the optical axis is used in the small-sized portable camera, drive loss is increased since a direction of thrust and a moving direction of the lens are not the same. Accordingly, there is a possibility that a moving speed of the lens will be decreased and responsivity will become slow.